package com.itheima.controller;


import cn.hutool.core.lang.UUID;
import com.itheima.util.Result;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

/**
 * 文件上传与管理
 */
@RestController
@RequestMapping("/common")
public class CommonController {

    @Value("${reggie.path}")
    private String path;

    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public Result upload(MultipartFile file){
        //获得原始文件名
        String originalFilename = file.getOriginalFilename();
        //截取“.jpg”
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID重新生成文件名，防止文件名字重复
        String fileName = UUID.randomUUID().toString() + suffix;
        //创建一个目录对象
        File dir = new File(path);
        if (!dir.exists()) {
            //如果不存在需要创建
            dir.mkdirs();
        }
        try {
            file.transferTo(new File(path+fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return Result.success(fileName);
    }

    @GetMapping("/download")
    public void download(String name , HttpServletResponse response){
        //输入流，通过输入流读取文件内容
        try {
            FileInputStream fileInputStream = new FileInputStream(new File(path+name));
            //通过输出流，通过输出流将文件写回浏览器，在浏览器中展示图片
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = fileInputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
